(And a sign for them) means, evidence for them of the existence of the Creator and His perfect power and ability to resurrect the dead,

﴿الاٌّرْضُ الْمَيْتَةُ﴾

(is the dead land.) means, when it is dead and arid, with no vegetation, then Allah sends water upon it, it is stirred (to life), and it swells and puts forth every lovely kind (of growth). Allah says:

﴿أَحْيَيْنَـهَا وَأَخْرَجْنَا مِنْهَا حَبّاً فَمِنْهُ يَأْكُلُونَ﴾

(We give it life, and We bring forth from it grains, so that they eat thereof.) meaning, `We have made it a provision for them and their cattle.'

(And We have made therein gardens of date palms and grapes, and We have caused springs of water to gush forth therein.) means, `We have created therein rivers which flow to the places where they are needed, so that they may eat of their fruits.' When Allah reminds them of the blessing that He bestows upon His creation by creating crops and plants, He mentions the different types and kinds of fruits. Allah says:

﴿وَمَا عَمِلَتْهُ أَيْدِيهِمْ﴾

(and their hands made it not.) means, all of that could only come about by the mercy of Allah towards them, not by their own efforts and labor and strength. This was the view of Ibn `Abbas and Qatadah. Allah says:

﴿أَفَلاَ يَشْكُرُونَ﴾

(Will they not then give thanks) meaning, will they not then give thanks for the innumerable blessings that He has bestowed upon them. Ibn Jarir, however, understood the word Ma to mean Alladhi (i.e., a relative pronoun). In this case the meaning of the Ayah would be that they eat from the fruits provided by Allah's bounty and from what their own hands have done, i.e., by planting the seeds and tending the plants. Ibn Jarir mentioned other possible interpretations in his Tafsir, but this is the interpretation that he favored. This interpretation also fits with the recitation of Ibn Mas`ud: (لِيَأْكُلُوا مِنْ ثَمَرِهِ وَمِمَّا عَمِلَتْهُ أَيْدِيهِمْ أَفَلَا يَشْكُرُونَ) (So that they may eat of the fruit thereof -- and from what their own hands have done.) Then Allah says:

(37. And a sign for them is the night. We withdraw therefrom the day, and behold, they are in darkness.) (38. And the sun runs on its fixed course for a term (appointed). That is the decree of the Almighty, the All-Knowing.) (39. And the moon, We have decreed for it stages, till it returns like the old dried curved date stalk.) (40. It is not for the sun to overtake the moon, nor does the night outstrip the day. They all float, each in an orbit.)